Study On Interaction Law Of Tunnel Surrounding Rock And Lining Structure Considering Creep Characteristics

The construction of the tunnel project is a fundamental task crucial for generations to come,it is required to ensure the safety and reliability of the tunnel structure during this period,the creep characteristics of tunnel surrounding rock are important factors affecting the safety and normal use of tunnel structure,therefore,it is very important to study the influence of the creep characteristics of surrounding rock on the stress characteristics of the tunnel lining structure.In view of the above problems,this paper relies on the tunnel in Tangjiayuan tunnel,theoretical analysis and numerical simulation study on interaction law of tunnel surrounding rock and lining structure considering creep characteristics are made:1.The rheological propertys and applicable rock mass types of the rheological models are summarized and analyzed.According to Tangjiayuan tunnel deformation monitoring data,select the Burgers model for the creep model of the tunnel surrounding rock.2.By using the displacement back analysis method,based on the theoretical calculation and actual tunnel monitoring data,to analyse the creep parameters of the Burgers model of the surrounding rock of the Tangjiayuan tunnel,obtained the creep parameters of tunnel surrounding rock.3.The tunnel surrounding rock creep as medium,and in accordance with the Buegers model,the lining structure is regarded as an elastic body,by using the corresponding principle of elastic viscoelasticity,derived circular tunnel interaction in two to isobaric conditions of surrounding rock and lining between the time-dependent solution,further according to the design specification of the tunnel safety factor of lining,the lining safety coefficient of the viscoelastic solution is obtained.4.The Tangjiayuan tunnel is converted into a circular tunnel by using the "equivalent radius method",and obtains the interaction variation law of Tangjiayuan tunnel liningstructure and surrounding rock,further analysis of the lining safety coefficient,obtained the change curve of Tangjiayuan tunnel lining safety coefficient within the design life.5.By using FLAC3 D numerical simulation software,the stress distribution and variation characteristics of the tunnel lining structure under the creep of the tunnel are analyzed.The conclusions were obtained: 10 years ago after the completion of the tunnel construction,tunnel lining structure is affected by the creep characteristics of the rock mass is relatively obvious,but in the next 10 to 40 years is the stress gradually after adjustment,is a relatively stable stage,although the lining stress is still increased,but the increasing speed is very small.6.Comparative analysis of the structure characteristics of tunnel lining and surrounding rock at the point of the interaction theory and simulation values,the results show that the theoretical values and simulation values are not entirely consistent,but the change trend and scope of roughly the same,demonstrate the applicability of the theoretical calculation,and has certain guiding significance to the actual project.